Previously, many types of rescue tools have been used to provide an effective means to pry or cut open a damaged vehicle at the scene of an accident. Other machine tools have also been developed with similar operational characteristics.
A search of the prior art did not disclose any patents that read directly on the claims of the instant invention, however the following U.S. patents are considered related:
U.S. Pat. No.InventorIssue Date6,244,568PattonJun. 12, 20015,956,992PattonSep. 28, 19995,622,353Painter et al.Apr. 22, 19975,301,533JacksonApr. 12, 19944,734,983BrickApr. 5, 19884,392,263AmorosoJul. 12, 19834,333,330PorterJun. 8, 1982
Patton's own U.S. Pat. No. 6,244,568 teaches a rescue spreading tool that provides spreading, crushing or cutting. A stationary yoke is attached to a cylinder and pair of spreader arms are attached to the cylinder and are free to rotate in opposite directions. Integrally formed with the cylinder ram is a pusher cam yoke that engages the arms and pushes them apart when the ram is extended. A pair of toggle links attached to the yoke continue to push the arms apart, thus creating a secondary thrust.
U.S. Pat. No. 5,956,992 also issued to the instant inventor, Patton, is for the same utility as above and consists of a first arm which functions in combination with an interlocking second arm that operates with a drive yoke. Another yoke includes a pair of cam pins that traverse a cam slot in each arm, and a drive rod is connected to the drive yoke.
Painter et al in U.S. Pat. No. 5,622,353 discloses a rescue tool having a pair of spreader arms with a pivot point therebetween. A pair of links attached to the arms are reciprocally moveable between retracted and extended positions along an axis of movement. A third pivotal coupling couples the spreader arm pivot point to the housing.
U.S. Pat. No. 5,301,533 of Jackson discloses a machine tool that relates to manufacturing operations for gripping, clamping, piercing and hemming workpieces. Two pairs of arms are arranged in an opposed, inverted relationship with respect to each other and are pivotally connected at one end to a drive. Each arm has a cam formed therein. The cams in each pair of arms are identically constructed in an opposed inverted relationship. Cam followers are mounted on a linear drive member, which engages the cams during movement to pivot the arms between an open and closed position. Each cam has an arcuate shape at an obtuse angle with respect to a pivot pin connecting each pair of arms.
U.S. Pat. No. 4,734,983 issued to Brick teaches a cutting tool that is effective for cutting through sheet metal when extricating accident victims. The tool has one curved movable blade and one stationary blade. The stationary blade is formed on an anvil that is anchored within the frame of the tool and is locked within the frame with a dowel.
Amoroso in U.S. Pat. No. 4,392,263 teaches a rescue tool having a body with a cylinder and an outward extending piston. Jaw members are connected to the body with links and include outer prying portions, inner cutting portions and intermediate shearing portions. The tool may be powered by a bi-directional motor or directly from a wrecker motor vehicle system.
U.S. Pat. No. 4,333,330 issued to Porter is for a spreader tool that has opposed force arms that are separated and pivoted while mounted on a base member. The arms achieve annular movement in an opposite direction in response to axial movement of a driven piston of an associated jack. The arms have inner edges that rest upon rollers mounted on the forward end of the piston. The curve of the arm's inner edges forms an angle at which a constant axial force of the piston is applied to the arm by the roller such that the force is always constant.
For background purposes and as indicative of the art to which the invention is related, reference may be made to the remaining cited patents issued to Gehron in U.S. Pat. No. 5,425,260 and Forster et al in U.S. Pat. No. 4,886,635.